Deck 1: Structure and Bonding:acids and Bases

Question 1

The molecular formula C₂H₄O can be converted into three-line bond (Kekulé) structures that are consistent with valence rules. Which one of the following Kekulé structures is not consistent with valence rules?

A)
B)
C)
D)

Answer 1

Question 2

Instructions: Determine the hybridization for the indicated atoms in each structure below.
Refer to instructions. The hybridization of carbon atom A is _____.

Answer 2

sp²

Question 3

Instructions: Propose a structure for a molecule that meets the following description.
Refer to instructions. Contains only one sp³ hybridized carbon and two sp² hybridized carbons.

Answer 3

Question 4

How many nonbonding electron pairs are in the structure shown below?

A) 2
B) 4
C) 6
D) 8
E) none of these

Question 5

Which of the following best represents the shape of a sp³ hybrid orbital of carbon?

A) 1
B) 2
C) 3
D) 4

Question 6

Which of the following statements is not true?

A) The carbon-carbon single bond of an alkane is weaker than the carbon-carbon triple bond of an alkyne.
B) The carbon-carbon triple bond of an alkyne is shorter than the carbon-carbon double bond of an alkene.
C) The carbon-carbon triple bond of an alkyne is exactly three times as strong as a carbon-carbon single bond of an alkane.
D) The carbon-carbon single bond of an alkane is longer than the carbon-carbon triple bond of an alkyne.

Question 7

Draw the structure for CCl₂F₂ using solid, wedged, and dashed lines to show the tetrahedral geometry.

Question 8

Draw all the lone pairs (nonbonding valence electrons) on the structure of phosgene, a poisonous gas once used as a chemical warfare agent.

Question 9

Convert the skeletal drawing of the pharmaceutical Vioxx into a molecular formula.

Question 10

Specify the hybridization of each carbon atom of limonene, a natural product present in citrus fruits, and thujone, which is derived from wormwood, a traditional component of the notorious liquor, Absinthe.

Question 11

Consider the formation of an sp² hybrid orbital. Which of the following is true?

A) Four equivalent hybrid orbitals are produced.
B) One s and one p atomic orbital are involved.
C) One p atomic orbital remains unhybridized.
D) The hybrid orbitals produced can form $\pi$ bonds.
E) none of these

Question 12

Instructions: Propose a structure for a molecule that meets the following description.
Refer to instructions. Contains only two sp³ hybridized carbons and two sp hybridized carbons.

Question 13

The structure of urea is shown below. Fill in any nonbonding valence electrons that are missing from the line-bond structure.

Question 14

Instructions: Write valid Lewis (electron-dot) structures for each formula below. Show all electrons as dots and show all nonbonding electrons.
Write:
CH₃CH₂OH ethanol

Question 15

In drawing the Lewis structure for an organic compound, the carbon atoms should always be shown with

A) lone pairs of electrons.
B) four single bonds.
C) eight total electrons.
D) a positive charge.
E) none of these

Question 16

According to atomic theory:

A) the nucleus is positively charged.
B) the nucleus contains both charged and uncharged particles.
C) the electrons contribute very little to the total mass of the atom.
D) the electrons are located in the atomic space outside the nucleus.
E) all of these

Question 17

Covalent bonding

A) involves a transfer of electrons from one atom to another.
B) occurs when atoms share all their valence electrons.
C) occurs when unpaired valence electrons are shared between atoms.
D) occurs when nonvalence electrons are shared between atoms.
E) none of these

Question 18

How many total valence electrons are represented in the following electron configuration? 1s²2s²2p_x² 2p_y² 2p_z¹ or 1s²2s²2p⁵

A) 1
B) 3
C) 5
D) 7
E) 9

Question 19

Which of the following best represents the shape of a 2p atomic orbital of carbon?

A) 1
B) 2
C) 3
D) 4

Question 20

Instructions: Determine the hybridization for the indicated atoms in each structure below.
Refer to instructions. The hybridization of carbon atom B is _____.

Question 21

The following shows an intermediate used in a Grignard synthesis. Which atom will inductively donate electrons in this species?

A) C
B) Br
C) Mg
D) H
E) both b and c

Question 22

Of the bonds found in which is the most polar?

A) C-F
B) O-H
C) C-H
D) C-O

Question 23

Instructions: Label the acid and base in each reaction below.
Label:

Question 24

Instructions: Refer to the following equation to answer the question(s) below.
Refer to instructions. The strongest Brønsted-Lowry acid in the equation is indicated by letter _____.

Question 25

Instructions: Use the convention $\delta$ / $\delta$ + and the crossed arrow to show the direction of the expected polarity of the indicated bonds in the following compound(s).

-Refer to instructions. A C-O bond in tetrahydrofuran,

Question 26

Draw a Lewis structure for each of the following.
a)hydroxylammonium ion: ⁺NH₃OH.
b)azide ion: (N₃^-)

Question 27

Instructions: Refer to the following equation to answer the question(s) below.
Refer to instructions. The strongest Brønsted-Lowry base in the equation is indicated by letter _____.

Question 28

Instructions: Consider the reaction below to answer the following question.
Refer to instructions. Using the curved arrow formalism, show the flow of electrons for this reaction.

Question 29

Instructions: Consider the two structures below to answer the following question.
CH₃CH₂OH CH₃OCH₃

-Refer to instructions. Which of the following correctly describes the structure of these compounds?

A) All carbon atoms are sp³ hybridized.
B) All of the bonds are sigma bonds.
C) Each oxygen atom has two nonbonding pairs of electrons.
D) The bond angle around each oxygen atom is ideally about 109.5 $\degree$ .
E) All of these

Question 30

Use the curved arrow method to show the electron movement, and label the acid, base, conjugate acid, and conjugate base.

Question 31

Which is the strongest base (pK_a values given for conjugate acid)?

A) NH₃ (pK_a = 9.2)
B) CH₃O ^- (pK_a = 16)
C) (pK_a = -6.5)
D)CH₃CO₂ ^- (pK_a = 4.7)
E)(H ^- (pK_a = 35))

Question 32

Instructions: Consider the two structures below to answer the following question.
CH₃CH₂OH CH₃OCH₃

-In the two structures shown below, what do the positions labeled with the arrow have in common?

A) the same type of hybridization on the carbon atom
B) the same geometry around the carbon atom
C) the same number of hydrogen atoms bonded to the carbon atom
D) both carbon atoms are involved in a $\pi$ bond

Question 33

Identify the reactants and product in the reaction below as acids or bases and specify whether they are Lewis and/or Brønsted-Lowry.

Question 34

Instructions: Use the convention $\delta$ / $\delta$ + and the crossed arrow to show the direction of the expected polarity of the indicated bonds in the following compound(s).

-Refer to instructions. The C-F bond in fluorobenzene,

Question 35

Consider the structure of acetic acid shown below. In the electrostatic potential map of acetic acid, in which of the following bonds would the terminal atom appear as the deepest shade of red?

A) C=O
B) C-H
C) C-C
D) O-H

Question 36

Instructions: Refer to the following equation to answer the question(s) below.
Refer to instructions. Will this reaction take place as written in the forward direction? Explain.

Question 37

Instructions: Indole is pleasant smelling in highly dilute solutions and has been used in perfumery. Use the structure of indole, below, to answer the following question(s).
Refer to instructions. Indole can function as a Lewis base in the presence of strong acid. Formulate a reaction, using a generic acid (HA), showing electron flow with arrows, that demonstrates this reactivity of indole.

Question 38

Instructions: Consider the species below to answer the following question.

Refer to instructions. Which of the following would be common to all?

A) Lewis acids
B) Lewis bases
C) Lewis acids or bases
D) Neither Lewis acids nor bases

Question 39

Circle the Lewis bases in the group of compounds below.

Question 40

Instructions: Indole is pleasant smelling in highly dilute solutions and has been used in perfumery. Use the structure of indole, below, to answer the following question(s).

-Refer to instructions. Indole can function as a Brønsted-Lowry acid in the presence of strong bases. Formulate a reaction, using a generic base (:B^-), showing electron flow with arrows, that demonstrates this reactivity of indole.

Question 41

Write an equation for the reaction of boron trifluoride, an important reagent in organic chemistry, with trimethylamine. Represent the movement of electrons with a curved arrow, and show the formal charges on the atoms in the product.